Calibration

Sometimes, at the beginning or end of each ECG strip, you will find a steplike structure called a calibration box. The standard box is 10 mm high and 0.20 seconds wide (Figure 3-2A). The calibration box is there to confirm that the ECG recording conforms to the standard format.

Three illustrations, A through C, show the types of calibration in an ECG paper.

Figure 3-2 Three types of calibration.

© Jones & Bartlett Learning.

Description

Occasionally, you will find that an ECG has been formatted in half-standard calibration (Figure 3-2B). This is usually done when the complexes are so tall that they run into each other. You will know that it is half-standard because there will be an additional step halfway up the box that lasts for half the width of the standard box. When you see this stairlike configuration, you are at half-standard.

The only other calibration you will run across is one in which the paper speed is set to 50 mm/sec, instead of the traditional 25 mm/sec. In this case, the calibration box will be 0.40 seconds wide (Figure 3-2C).